摘要目的 以胸部X线定位为"金标准",分析改良微泡实验法识别经外周静脉置入中心静脉导管(PICC)尖端在位的特异度和敏感度,寻找一种可节约时间和成本、准确且无创的PICC尖端定位方法.方法 采用方便抽样法,选择2017年8月至2018年2月在南昌大学第一附属医院重症加强治疗病房(ICU)和PICC门诊接受经超声引导下PICC置管的患者.纳入患者均依次完成超声引导下PICC置管、改良微泡实验法、胸部X线定位.分析改良微泡实验法中微泡密度分级与胸部X线定位PICC尖端位置的关系;以胸部X线定位为"金标准",计算改良微泡实验法识别PICC尖端在位的特异度和敏感度等诊断性评价指标.结果 研究期间共120例患者入选,排除拒绝参加本研究、右心房超声不清晰、自觉不耐受、胸部X线不清晰者,最终108例患者均完成改良微泡实验和胸部X线尖端定位.根据胸部X线定位结果,108例患者中PICC尖端理想位置69例(63.9%),非理想位置33例(30.6%),异位6例(5.5%);3组患者间性别、年龄、置管肢体、置管深度、置管科室、置管静脉差异均无统计学意义.108例患者中改良微泡实验法Ⅰ级微泡74例(68.5%),Ⅱ级微泡25例(23.2%),Ⅲ级微泡9例(8.3%).微泡密度与导管尖端位置存在相关性,呈中强度相关,列联系数C为0.662.改良微泡实验法判断PICC尖端在位的敏感度为95.7%(66/69),特异度为89.7%(35/39),漏诊率为4.4%(3/69),误诊率为10.3%(4/39),阳性预测值为94.3%(66/70),阴性预测值为92.1%(35/38),约登指数为0.85 ;两种方法判断结果的一致性较好,Kappa值为0.86.结论 与胸部X线定位法相比,改良微泡实验法识别PICC在位的敏感度、特异度均较高,且操作简单、无创、用时少、费用低;可作为PICC二次调管的筛选性检查,尤其在ICU,有技术限制或尖端位置可疑者应再进行胸部X线定位.

abstractsObjective To analyze the specificity and sensitivity of the modified microbubble test in identifying the peripherally inserted central venous catheters (PICC) tip based on the chest X-ray location as the"gold standard", and to find out an accurate and noninvasive PICC tip positioning method that can save time and cost. Methods Convenient sampling method was conducted. The patients under PICC guided by ultrasound in intensive care unit (ICU) or PICC clinic of the First Affiliated Hospital of Nanchang University from August 2017 to February 2018 were enrolled. All patients were followed up by ultrasound guided PICC catheter placement, modified microbubble test and chest X-ray localization. The relationship between the density of microbubbles in modified microbubble test and the location of PICC tip in chest X-ray localization was analyzed. Using chest X-ray localization as the "gold standard", the diagnostic evaluation indexes such as specificity and sensitivity of PICC tip identification by modified microbubble test were calculated. Results A total of 120 patients were enrolled during the study period, excluding those who refused to participate in the study, unclear right atrial ultrasound, conscious intolerance, unclear chest X-ray, and finally 108 patients completed the modified microbubble test and chest X-ray tip localization. According to the chest X-ray localization results of 108 patients, 69 patients (63.9%) were in ideal locations, 33 (30.6%) were in dissatisfactory position, and 6 (5.5%) were in malposition. There was no significant difference in gender, age, tube placement, depth of catheterization, placement of catheterization room, and catheterization among the three groups. In the modified microbubble test, there were 74 patients (68.5%) with gradeⅠmicrobubble, 25 (23.2%) with gradeⅡmicrobubble, and 9 (8.3%) with grade Ⅲ microbubble. There was a correlation between microbubble density and the tip position of the catheter, showing a moderate intensity correlation, and the contingency coefficient was 0.662. The sensitivity of the modified microbubble test for PICC tip positioning was 95.7% (66/69), the specificity was 89.7% (35/39), the rate of missed diagnosis was 4.4% (3/69), the misdiagnosis rate was 10.3% (4/39), the positive predictive value was 94.3% (66/70), the negative predictive value was 92.1% (35/38), and the Youden index was 0.85. The consistency between the two methods was good, and the Kappa value was 0.86. Conclusions Compared with the chest X-ray localization method, the modified microbubble test method has high sensitivity and specificity in identifying PICC in the position, and the operation is simple, noninvasive, with less time and low cost. The modified microbubble test can be used as a screening test for PICC tip position, especially in ICU. When there are technical limitations or suspicious patient, further chest X-ray is necessary.